Yeah, I too have my doubts about thin flimsy wraps (obviously, animals can penetrate them easily)… but, I am more confident, after a bit of reading/research.
I am not sure how it works, but I assume (even though it’s thin, soft and easily penetrated) when an animal (rabbit, rat, squirrel, deer) encounters the fluffy/soft/fibrous wrap, it probably assumes that the entire tree/trunk is the same material… so it moves on (as it might prefer to chew on hard, brittle, flaky, tough bark and trunks instead). That’s my guess anyways.
As for critter repellent sprays (with capsaicin/pepper, blood, rotten egg, garlic, aroma oils, etc.), I’ve been using them for a while now, and they seemed to work, until just last spring… all my JMs, 3 satsuki and a large crop of newly rooted satsuki cuttings (6 pots, 15-20 cuttings in each pot) were decimated just 1-2 weeks after I sprayed (I thoroughly heavily spray too - entire plant, trunk, foliage, pots, soil, ground close to pots, walls close to pots, etc.). That signaled to me that I will stop buying/using those sprays, lol. Waste of money and time from that experience.
Sprays aren’t good, imo… because, even if they did actually work, once you stop or forget, then game over.
Yeah… foliage is an issue too. But the tree has a higher survivability chance with just the foliage getting messed with… so I’m trying to remedy the trunk problem first.
I did cover my side gates to the backyard with 3’ tall wire fence though… so no rabbits there… just the front-yard.
Yeah… for shorter shrubs and foundation plants, I may just cut to the chase and use hardware-cloth wire cages. And for taller single trunk trees, wraps and/or pipes as you suggested.